How import TLS certificate into v2ray plugin

I have Shadowsocks and v2ray-plugin installed on a CentOS 7 server. It is set up with Caddy and has a Let’s Encrypt SSL cert.

How do you install the cert in the Android Shadowsocks app? I installed the v2ray Plugin and under the v2ray settings, is an option to add the Certificate for TLS verification. I have downloaded the cert to the phone and tried to select it but it will not import it. I have tried it with a crt and cer extension.

You don’t need to import anything